The present invention relates to an apparatus and a method for freezing material, such as foodstuff, into portions by positioning the material divided into portions on a sheet and passing it over a contact freezing refrigerating panel. The present invention allows freezing of viscous material into portions of controlled shape and size. The present invention also relates to blocks frozen in accordance with the method or by means of the apparatus of the invention.
The present invention is especially suitable for freezing viscous foodstuff materials with or without solid pieces. For example, sauce, pieces of vegetables, meat, or mixtures thereof. The invention may advantageously be used for freezing portions weighting from 5 to 200 g or more.
A traditional way of freezing food material is by pouring the material into molds which are then cooled. This is a relatively slow way of freezing due to the very little if any direct contact with the cooling medium. Another disadvantage of this traditional mold is that releasing the frozen material from the mold is difficult due to the increased in size of the frozen material.
It is also known to chill and freeze food material by depositing it onto a sheet and passing the sheet over a contact freezing surface so as to provide, at least on its lower surface, a frozen crust. The contact freezer has the advantage that it provides fast freezing as a result of the contact between the material to be frozen and the cooling surface, while the thin sheet prevents the material from sticking to the cooling surface. Another way of freezing food material is by depositing it onto a steel belt and cooling it with nitrogen.
However, these known freezing methods suffer from the problem of controlling the shape and size of the material to be frozen, and are unsuitable for freezing composite or layered products. When dosing viscous material onto a sheet or belt it will evidently spread resulting in a flat pellet type end product. Furthermore, there is a risk that the separately dosed material will flow into the other doses and thus freeze into bigger lumps.